Satellite imagery shows about 60 square miles of marsh were ripped up and submerged around New Orleans, said John Barras of the U.S. Geological Survey, with another 40 square miles turned into open water across the state's coast.

At a meeting to discuss the damage, the U.S. Geological Survey said it's too early to tell how much of the open water will revert back to marshland, but the agency said it's very likely that many new lakes will form.

"Some of the larger rips will remain as permanent ponds unless sediment is put in them or some appropriate restoration project is done," Barras said.

The damage adds to Louisiana's already dire coastal land loss. The state has lost about 1,900 square miles of coastal wetlands since the 1930s due to levee building, oil and natural gas drilling and natural causes. The agency had previously estimated that the coast would lose about 650 square miles of marsh by 2050.

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Louisiana's marshes are a prime habitat for fish and a barrier against potential storm surges from future hurricanes.

"The enormity of the disaster is hard to put in words, especially if you've flown over the areas," said Col. Richard Wagenaar, the U.S. Army Corps of Engineers district chief in New Orleans. Wagenaar oversees the committee steering efforts to restore coastal Louisiana.

In the end, the damage may exceed 100 square miles of marsh loss, officials said.

The storms inundated fresh marshes with salt water and killed marsh grasses, said Ronny Paille, a biologist with the U.S. Fish and Wildlife Service.

"It looks stone cold dead," he said about the marshes. It will take another growing season or two to see if the marsh springs back, he said.